Knead the flour, 60 g sugar, 1 packet vanilla sugar, egg and 125 g butter in pieces first with the dough hooks of the hand mixer then with your hands to a smooth dough. Cover and chill for about 30 minutes.
Bring 250 g butter, 200 g sugar, 1 sachet vanilla sugar and 4 tablespoons water to the boil. Let cool for about 10 minutes. Coarsely chop the pecans. Stir almonds and pecans into the warm butter-sugar mixture
Grease the fat pan of the oven (32 x 39 cm) and dust with flour. Roll out dough to approx. 2/3 in the fat pan. Press a multiple-folded aluminium strip against the dough as a border. Spread nut mixture on the dough and spread
Bake in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) for 25-35 minutes on the lower rack until golden brown. Remove from the oven and allow to cool on a cake rack for about 15 minutes. Use an electric knife to cut the dough sheet into squares of approx. 3 x 3 cm. Let it cool down. Decorate with caramelized pecans if desired
Waiting time approx. 30 minutes